Create a working microscope in Blender?
Just for fun, you can also get good results with Cycles.  

Glass shader with IOR = 1,6 (same as Crown glass used in microscopes)
And a rather simple microscope setup.

Original image with a tiny Suzanne


Magnified using a microscope


Diagram of used setup


Notes:
Cycles, 100 samples + Intel Denoiser
I'm sure better results can be achieved by playing with the lens setup.
Bottom line, it works :).